Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!samsung!spool.mu.edu!uunet!aplcomm!tedwards
From: tedwards@aplcomm.JHUAPL.EDU (Edwards Thomas G S1A x8297)
Newsgroups: sci.electronics
Subject: Re: Wanted RADAR kit, was (Re: Measuring vehicle speed)
Summary: Yes, it's a real radar
Message-ID: <470@aplcomm.JHUAPL.EDU>
Date: 27 Jun 91 18:58:35 GMT
References: <1991Jun24.205716.29809@cci632.cci.com> <1840053@hpsad.HP.COM>
Reply-To: tedwards@aplcomm.jhuapl.edu (Edwards Thomas G S1A x8297 )
Organization: JHU/APL, Laurel, MD
Lines: 17

In article <1840053@hpsad.HP.COM> frankb@hpsad.HP.COM (Frank Ball) writes:
>> Ramsey Electronics sells a radar speed indicator kit for under $100.

>Just what is this kit?  Is is really RADAR? or is it SONAR (ultrasonic)?
>or maybe LASER (with a diode?)?

Negative.  It is a real working radar.  I have seen a static display of it
working at a HamFest.  If you wave your hand back and forth at high
speed in front of the "gun" made from the tennis ball can, you can see
your hand speed displayed.  I assume it is just a little gunn oscillator,
and you mix the return with the xmitted signal (either electronically
or in the waveguide...I don't do microwaves) and it looks at the
sum or difference frequency and converts it to a speed.  
I have no idea how accurate this thing is, or how much range it has,
but they claimed it could be used for measuring speeds of passing cars.

-Tom